Composite wood-metal structural unit



Dec'. 3, 1929. s. MACOMBER COMPOSITE WOOD METAL STRUCTURAL UNIT Filed Dec. 24, 1927 Patented Dec. 3, 1929 TATES OFFEQE STANLEY MAGOMBER, OF EDGEFIELD DISTRICT, OHIO COMPOSITE \VOOD-METAL STRUCTURAL 'lIJ'NI'I' This invention relates to improvements in structural units of the general type shown in my United States Patent No. 1,651,032. In said patent there is disclosed a metal unit of a light trusslike structure adapted for use instead of beams in carrying light loads, as in the case or floor joists, columns, roof purlins, and reinforcement for concrete floors, etc. The invention comprises, as illustrated in that patent, a truss center and extension beam ends whereby with a minimum amount of material the unit is designed to carry a predetermined load and at the same time provide, together with other described advantages, a flexibility as to the span which the unit can cover. The present invention relates to improvements in a joist of this general character for use in competition with or as a substitute for wood supports in wood floor construction.

The particular improvements of the present invention consist in replacin the upper metal chord of the joist of said Patent No. 1,651,032 with a wood nailing strip, in combination with a small connecting angle running lengthwise of the wood strip and serving to attach the web bar securely and carry the stresses to the nailing strip. necting angle also directly carries a minor portion of the stresses. Such an improved construction greatly cheapens and lightens the joist, while at the same time adequately caring for the stresses which the several parts of the joist should withstand and the stress load which the unit as a whole should carry. Also, economy in installation is eftected in thus being enabled to provide the necessary nailing strip which, otherwise, would require extra operations and additional members.

The annexed drawing and the following description set forth in detail certain means embodying my invention, such disclosed means showing, however, but one of the various forms in which the principle of the invention may be exemplified.

In said annexed drawing:

Figure 1 is a broken side elevation of the complete joist;

This con-v Figure 2 is a perspective View of one end oi the joist; and

Figures 3, 4-, 5, and 6 are transverse vertical sections, uponan enlarged scale, taken, respectively, in the planes denoted b the lines IIIIII, IVIV, V-V, and VIVI,

Figure 1.

Referring to the annexed drawing in which the same parts are indicated by the same respective ordinals in the several views, I show a wood strip 1 which is a wood joist or timber of substantial cross-section and which will serve both for the usual nailing strip 01 wood floor construction, and,in connection with a metal angle hereinafter fully deserib'ed,carry the compression loads for which the joist is designec, in lieu of the usual. metal upper chord. To this nailing strip 1 and below the same I secure by bolts 8 an angle member running lengthwise of the joist and having the horizontal leg 2 and the vertical leg 3. Between the nailing strip 1 and the horizontal leg 2 of the connecting angle may be placed cushioning material such the felt strip 4; The lower chord of my improved joist is comprised ofa metal member 5 spaced from the upper wood-metal top chord and running substantially parallel with the latter throughout the major portion of its length, the ends of the member 5 being ex tended upwardly into the inclined portions 6 and thence horizontally into the end mem-,

bers 7 disposed closely adjacent the ends oi the nailing strip 1 and running parallel therewith. For purposes of illustration I have shown the bottom chord 5 as a round bar. Serving to connect the top and bottom chords is a continuous, reversely bent web member 9 whose angles 10 are connected in al ernate relation to the vertical leg 3 of the upper-chord connecting angle, and to the bottom chord 5, the connections preferably being made by means of welded oints 11 and 12, respectively. welded to, and preferably in the angles of, a pair 0t joist-end angle members having horizontal legs 16 and vertical legs 15, the latter being securedalong their upper edges to the vertical legs 3 of the top-chord connecting angle, the respective connections prefer The ends 7 of the bottom chord 5 are ably being made by welding, as illustrated by the respective ordinals 17 and 18, 19. The ends of the web-member 9 are turned upwardly into the inclined portions 13 and are secured by welded joints 14 to the inner portions of the vertical legs 15 of the respective end angles, as plainly shown in Fi ires 2 and .1. i

This improved joist can be supported to cover the given span at any desired point along the horizontal legs 16-01: the extended integrated end portions, These horizontal legs 16 of the end angles serve as continuous joist-end supporting members- The topchord connecting angle 23 serves as efli cient means for attaching the; intermediate web 9 and conveying the stresses t0 the nailingstrip, 1.v This connecting angle; 21-3 also directly carries aceltain part of the upper chord stresses,,b,ut the major portion of these stresses is cared for by the. wood; joist'l, t

By the constructiondescribed, and plainly shown. the accomp anying drawing, I proservei-the: general advantages of the strue tural unit described insaid Patent No..

1,651,032, and at'theisame time greatly decr-eascthe, weight :of lthesunit, for use in wood floor construction and; the cost of construction and installation of. the unit.

What I claim; is z y 1.. A compositewood-metal structural unit for use in Wo0dfloor constructions, comprisinga top chord consisting of aavoodjoist and a metal web-securing-member running lon ;git udinal 1y of and adjacently'beneath said wood joistland secured thereto,,.a; metal bottom chord, a metalweb-member connecting said, top and. bottom chords,, and metal unitend reinforcing means respectivelyconnected to and integrat ng the ends of sald chords andv said, web-member.

2. A, composite ,WDOd-HlGlZELl; structural unit for use in, wood floor COIlSlJILlCtlOIlS, COIIlPIlS-- ing a; toprchord consisting of a wood joist and ametal web-securing member running longitudinally of and'adj acently beneath said wOOdjoist and secured; thereto, in combinagitudinally ofand adjacently beneath said wood, joist. and, secured thereto a metal bottom 1, chord, spaced from said top chord and having its ends bent upwardlywintoclosely sroximate relationto thecorresponding ends of saidtop, chord,supporting unit end-metal angles respectively secured below and to the ends of said metal web-securing member and also secured to the ends of said bottom chord, and a metal web-member connecting said top and bottom chords, the extreme end portions of said web-member being secured to said supporting unit-end angles.

4 A composite wood-metalstructural unit for use in wood floor constructions comprising a top chord consisting of a wood joist and a metal aiigle secured by one leg to the bottom face of said wood joist and having its other legextended' downwardly, a metal bottomchord spaced from, said top chord and running parallel therewith for the major portionotits. length, the ends of-said. bottom chordabeing extended upwardly andv then.

horizontally in parallel closely proximate relation tethe corresponding ends ofsaidtop chord, supporting unit-end metal angles respectively securedby a, vertically-extended.

leg, to th downwardlyextending leg of said top-chord angle and havingtheir other. I'.e-

spective legs extended laterally,,the horizon,- tal end extensions of, the bottom chord being, secured respectively to the top faces ofthe,

laterally-extended legs oi. the ends angles, and" a continuous reversely bent metal. web- ,member connected at 1ts angles in alternate;

relation to the widely spacedparallel portions of said top and bottom chords, the extreme endiportions of said web-member being, secured respectively to the vertical legs of said, supporting unit-end angles.

Signed by me this 141th day of December,

STANLEY MACOMBER. 

